A hinge assembly having a pair of axially spaced hinge pins (commonly referred to as a twin pin lift off hinge) is described in our European Patent Specification 214468 and the hinge assembly of the present invention is particularly concerned with this type of hinge assembly.
According to one aspect of the present invention there is provided a hinge assembly having a first hinge leaf pivotally connected to a second hinge leaf by first and second axially aligned pivotal connections, the first and second pivotal connections being axially spaced from one another, a first stop means located adjacent to the first pivotal connection and a second stop means located adjacent to the second pivotal connection, the first and second stop means being arranged to simultaneously limit pivotal displacement between the first and second hinge leafs at a fully open position.
According to another aspect of the present invention there is provided a hinge assembly having a first hinge leaf pivotally connected to a second hinge leaf by a hinge pin, and a retention means for retaining the hinge leafs at a predetermined angular position, the retention means including a first latch formation connected to one hinge leaf so as to be rotationally fixed relative thereto and a second latch formation on the second hinge leaf, the first latch formation being biased toward the second hinge leaf so as to urge the first and second latch formations into engagement in said predetermined angular position, the first latch formation being removably mounted on the first hinge leaf.
Preferably the first latch formation is removably attached to the hinge pin. Preferably the first latch formation forms an integral part of a clip which is attachable to the hinge pin, the clip when attached to the hinge pin having a portion in abutment with the first hinge leaf to prevent rotation of the clip relative thereto.
According to a further aspect of the present invention there is provided a lift-off hinge assembly comprising a first hinge leaf hingedly connected to a second hinge leaf for relatively angular motion about a hinge axis, the first hinge leaf having a hinge pin fixedly mounted thereon and the second hinge leaf having a journal beating in which the hinge pin is received for rotation about said axis, the hinge pin being axially slidably received in the journal to enable axial separation of the first and second hinge leafs, removable stop means mounted on the hinge pin to prevent said axial separation, the second hinge leaf including a cam formation co-axially arranged with the hinge axis and having a cam face directed radially outwardly from said axis, the stop means including a cam follower means biased in a radially inward direction into contact with said cam face, the cam face and cam follower means co-operating to releasably retain the first and second hinge leafs at a predetermined angular position about said hinge axis.
Preferably the stop means comprises a body formed from a strip of resilient material, preferably spring steel.
The body is preferably cranked so as to form an anchorage portion which extends generally radially from said axis and a cam follower portion which extends generally parallel to said axis. Preferably the anchorage portion of the body is provided with an aperture through which the hinge pin passes, the location of the aperture from the cam follower portion being such that the body is placed under a resilient loading by reactive engagement between a rear wall portion of the aperture on the hinge pin and between the cam follower portion on the cam face.
Preferably the hinge pin is provided with a groove, preferably an annular groove, in which the anchorage portion is seated. The aperture is formed so as to be of a larger diameter than the shank of the hinge pin to enable it to be easily slid axially along the shank of the hinge pin.
Preferably, the rear wall portion of the aperture is formed so as to define a rigid shoulder ie. it defines a shoulder which prevents the anchorage portion from being pulled radially off the hinge pin.
The provision of the rigid shoulder enables a high resilient loading to be applied between the cam follower and cam face for holding the hinge leafs at said predetermined angular position.
Preferably the body co-operates with an abutment on the first hinge leaf to prevent relative rotation between the body and the first hinge leaf about said axis.
In one embodiment the aperture in the anchorage portion is continuously walled and a release ear is preferably formed on the anchorage portion on the opposite side of the hinge pin to the cam follower portion, the release ear providing a purchase location for gripping of the anchorage portion to enable it to be moved radially inwardly against said resilient loading to remove the rear wall portion of the aperture from said groove and thereby enable the body to be axially removed from the hinge pin.
In another embodiment, the anchorage portion is provided with an end portion located on the opposite side of the hinge pin to the cam follower portion, the end portion including a slit communicating with the aperture, which divides the end portion to define a pair of arms, each arm including a gripping formation to enable the arms to be gripped and spread apart to enlarge the aperture and enable the anchorage portion to be removed from the hinge pin. The cam face may include a recess or flat for co-operation with the cam follower portion for defining said predetermined position.
Various aspect of the present invention are hereinafter described with reference to the accompanying drawings, in which: